Products∣L. W. P. Enterprises Co., Ltd.

Material introduction

Principle on zinc-aluminum die-casting products

Die-casting principle ： A casting method that fills molten alloy liquid of metals with good melting properties such as aluminum, zinc, magnesium and copper into the metallic molds (heat-resistant steel) with a quick and high-pressure machine and the molten liquid quickly solidifies to form by the steel moulds having lower temperature.
Features of die-casting method ： High production, good size accuracy, less post-processing, smooth casting surface, high mechanical strength and can be fabricated to thin castings.

There are two major types of die-casting machines : Hot-chamber machine and cold-chamber machine. It can also be divided into vertical type and horizontal type in terms of its injection modes.
Hot-chamber : Applies to zinc-alloy materials.
Cold-type : Applies to aluminum alloy materials / zinc-alloy materials

Comparisons of zinc and aluminum alloys
Item Name	Zinc alloy	Aluminum alloy
Forming machines	Hot-type die-casting machine	Cold-type die-casting machine
Forming costs	Low	High
Forming temperature	Approx. 430°	Approx. 720°
Product size accuracy	High	Low
Mold cost	Low	Higher than zinc
Mold service life (accuracy requirement)	200,000~300,000 time-mold	80,000-100,000 time-mold
Forming burrs	Few	Plenty
Post-processing cost	Depends on the processing condition	Higher than zinc
Tensile strength	ZN3:29 ZN5:33	ADC10:33
Specific gravity	6.7	2.7
Material cost	Not much difference	Not much difference
Overall assessment : The object is small (light-weight <100g): Required size accuracy / high production – suitable for zinc alloys The object is large (light-weight >100g): Weight requirement (light) – more suitable for aluminum alloys

Physical Properties of Zinc Alloys
Designation	No.2(%)	No.3(%)	No.4(%)	No.5(%)	No.7(%)	ZA-8(%)	ZA-12(%)	ZA-27(%)
Density(g/cm)	6.6	6.6	6.6	6.6	6.6	6.3	6.0	5.0
Melting Range(C)	379-390	381-387	380-386	380-386	381-387	375-404	377-432	376-484
Electrical Conductivity(%IACS)	25	27	26-27	26	27	27.7	28.3	29.7
Thermal Conductivity(100c,W/m.k)	104.7	113	180.9 │ 113.0	108.9	11.3	114.7	116.1	125.5
Coefficient of Thermal Expansion (20-100c,um/mm/c)	27.8	27.4	27.4	27.4	27.4	23.3	24.2	26.0
Specific Heat(J/kg.k)	418.7	418.7	418.7	418.7	418.7	435.4	448.0	534.4
Die Shrinkage(mm/mm)	0.006	0.006	0.007	0.006	0.006	0.007	0.0075	0.008

Mechanical Properties of Zinc Alloys
Designation	No.2(%)	No.3(%)	No.4(%)	No.5(%)	No.7(%)	ZA-8(%)		ZA-12(%)		ZA-27(%)
Meehanical Properties	Die Cast	Die Cast	Die Cast	Die Cast	Die Cast	Die Cast	Sand Cast	Die Cast	Sand Cast	Die Cast	Sand Cast
Ultimate Tensile Strength(Mpa)	359	283	317	331	283	372	248 │ 276	400	276 │ 317	421	400 │ 440
Impact Strength(J)	47	58	61	65	58	42	20	28	25	-	47
Elongation(%)	7	10	7	7	13	6 │ 10	1 │ 2	4 │ 7	1 │ 3	1 │ 3	3 │ 6
Hardness(HB)	100	82	92	91	80	95 │ 110	80 │ 90	95 │ 115	90 │ 105	05 │ 125	110 │ 120
Shear Strength(MPa)	317	214	214 │ 262	262	262	275	-	275	-	296	255
Yield Strength(0.2%,MPa)	-	-	221 │ 269	-	-	290	200	317	207	365	365
Fatigue Strength Rotary Bend (5x10 cycle,MPa)	58.6	47.6	48 │ 57	56.5	-	-	-	-	103.5	-	172.5
Compressive Strength (0.1%m,MPa)	641	414	414 │ 600	600	600	252	199	252	199	269	227